BUDAPEST, Hungary (AP) — Hungarian water management authorities say the Danube River's high water levels, which have stymied efforts to reach a sunken tour boat where 21 missing people could be trapped, are falling.

The General Directorate of Water Management said Sunday the river has fallen 26 centimeters (10¼ inches) since midday Saturday, when it crested at 5.88 meters (19 feet, 3½ inches).

Divers may try to reach the wreck once the Danube falls to about 4 meters (13 feet), which is expected Wednesday, a week after a river cruise ship crashed into a tourist boat near the Margit Bridge in Budapest.

The sightseeing boat was carrying 33 South Koreans and two Hungarian crew members when it collided. Seven people were killed, seven were rescued and 21 others are still missing.